I never see owls during the day but regardless, traps are coming out for the others!First guess is possum, second would be skunk. Other possibilities are coon or owl.
I've never known anything that just ate the head. One head was gone except for the beak, the head bitten off cleanly, the other I would have suspected a snake because it was kind of crushed but the head wasn't missing. They were side by side when I found them.